Leaders of more than a dozen Caribbean countries are launching a united effort to seek compensation from three European nations for what they say is the lingering legacy of the Atlantic slave trade.

The Caribbean Community, a regional organisation, has taken up the cause of compensation for slavery and the genocide of native peoples and is preparing for what would likely be a drawn-out battle with the governments of Britain, France and the Netherlands.

It has engaged the British law firm of Leigh Day, which waged a successful fight for compensation for hundreds of Kenyans who were tortured by the British colonial government during the so-called Mau Mau rebellion of the 1950s and 1960s.

Lawyer Martyn Day said his first step would probably be to seek a negotiated settlement with the governments of France, Britain and Netherlands along the lines of the British agreement in June to issue a statement of regret and award compensation of £19.9m to the surviving Kenyans.

"I think they would undoubtedly want to try and see if this can be resolved amicably," Day said of the Caribbean countries. "But I think the reason they have hired us is that they want to show that they mean business."

Caricom is creating a reparations commission to press the issue, said Ralph Gonsalves, the prime minister of Saint Vincent and the Grenadines, who has been leading the effort.

The legacy of slavery includes widespread poverty and under-development, Gonsalves said. Any settlement should include a formal apology, but contrition alone would not be enough, he said.

"The apology is important but that is wholly insufficient," he said in a phone interview on Wednesday. "We have to have appropriate recompense."

The notion of forcing the countries that benefited from slavery to pay reparations has been a decades-long quest. Individual countries including Jamaica and Antigua and Barbuda already have national commissions.

Earlier this month, leaders from the 14 Caricom nations voted unanimously at a meeting in Trinidad to wage a joint campaign that those involved say would be more ambitious than any previous effort.

Each nation that does not have a national reparations commission agreed to set one up, sending a representative to the regional commission, which would be overseen by prime ministers. They agreed to focus on Britain on behalf of the English-speaking Caribbean, France for the slavery in Haiti and the Netherlands for Suriname.

Caribbean officials have not mentioned a compensation figure but Gonsalves and Verene Shepherd, chairwoman of the national reparations commission in Jamaica, both noted that Britain at the time of emancipation in 1834 paid £20m to British planters in the Caribbean, the equivalent of £200bn now.

The British high commissioner to Jamaica, David Fitton, said in a radio interview on Wednesday the Mau Mau case was not meant to be a precedent and that his government opposed reparations for slavery.

"We don't think the issue of reparations is the right way to address these issues," Fitton said. "It's not the right way to address an historical problem."

In 2007, marking the 200th anniversary of the British prohibition on the transportation of slaves, then prime minister Tony Blair expressed regret for the "unbearable suffering" caused by his country's role in slavery.

After the devastating Haitian earthquake in January 2010, then French president Nicolas Sarkozy was asked about reparations for slavery and the 90m gold francs demanded by Napoleon to recognise the country's independence. Sarkozy acknolwedged the "wounds of colonisation" and pointed out that France had cancelled a ¢56m debt to Paris and approved an aid package that included ¢40m in budget support for the Haitian government.

Gonsalves said much more needed to be done and he hoped to begin an "honest, sober and robust" discussion with the European governments soon, championing the issue when he takes over as chairman of Caricom in January.